🔐 CVE Alert

CVE-2026-84128

HIGH 8.8

Privilege escalation in the WebDriver BiDi component

CVSS Score
8.8
EPSS Score
0.0%
EPSS Percentile
0th

Privilege escalation in the WebDriver BiDi component. This vulnerability was fixed in Firefox 155 and Thunderbird 155.

Vendor mozilla
Product firefox
Ecosystems
Industries
Technology
Published Sep 1, 2026
Last Updated Sep 2, 2026
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Affected Versions

Mozilla / Firefox
All versions affected
Mozilla / Thunderbird
All versions affected

References

NVD ↗ CVE.org ↗ EPSS Data ↗
bugzilla.mozilla.org: https://bugzilla.mozilla.org/show_bug.cgi?id=2044280 mozilla.org: https://www.mozilla.org/security/advisories/mfsa2026-82/ mozilla.org: https://www.mozilla.org/security/advisories/mfsa2026-86/

Credits

Tomoya Nakanishi